LOS ANGELES (Reuters) - Reality TV star Khloe Kardashian will not be returning to "The X Factor" after just one season as co-host of the TV talent show.

Fox television on Monday announced that presenter and actor Mario Lopez would return for a second season but the statement made no mention of Kardashian.

An "X Factor" spokesman said Kardashian, 28, who with her California socialite sisters Kim and Kourtney rose to fame in "Keeping Up With the Kardashians," would not be returning when the U.S. version of the singing competition returns in September.

"We really enjoyed working with her and wish her all the best in the future," the spokesman said.

Kardashian, one of the most popular faces on U.S. television, was brought in by "X Factor" creator Simon Cowell last year as part of a revamp that included the hiring of singers Britney Spears and Demi Lovato as judges after a disappointing first season in 2011.

A source close to the show said Kardashian, who had no previous experience as a TV host, was not asked to renew her contract.

Spears quit after one season and her replacement has yet to be named but Lovato will be back in September.

Kardashian married basketball player Lamar Odom in 2009, and the pair got their own spinoff show. She has more than 8 million followers on Twitter and has been in the news for several months over the couple's efforts to have a baby.

Lopez, a former actor, is the co-host of entertainment magazine show "Extra" and radio show "On with Mario Lopez." He is also an author of several fitness books.

"I'm thrilled Mario is back for Season Three of 'The X Factor,'" Cowell said in a statement. "Hosting a live show and keeping the judges - especially Demi - in line, is not an easy job, but Mario is a pro and we are glad he's coming back."